The effect of age on self-rated skin pain in patients with hidradenitis suppurativa.

BACKGROUND Hidradenitis suppurativa (HS) is a recalcitrant chronic inflammatory skin disease characterized by recurrent and painful nodules that negatively affect health-related quality of life. Pain is the most disabling symptom of HS, but data on HS pain remain limited. We previously observed a dissociation between pain and number of HS lesions with regards to increasing age. OBJECTIVES To further explore this observation, we investigated the relationship between experienced HS pain and age, adjusting for other relevant factors that might affect pain assessment. MATERIALS & METHODS We conducted a retrospective cohort study (n = 342) using data from the Registry for Hidradenitis Suppurativa database. Multiple linear regression analysis was performed for self-evaluated pain (measured on a 0-10 numerical rating scale [NRS]) as an outcome with age and adjusted for the effects of sex, BMI, smoking status, lesion count and percentage of lifetime spent with HS symptoms. RESULTS The multiple linear regression showed that age was associated with a decreased pain level of 0.31 NRS points/year (95% CI: -0.062; -0.0088; p = 0.044) and number of nodules was associated with an increased pain level of 0.081 NRS points/nodule (95% CI: 0.00077; 0.16; p = 0.048). Percentage of lifetime spent with HS symptoms was not found to significantly affect pain levels. CONCLUSION This study supports our hypothesis that older HS patients report decreased levels of pain, independent of disease severity, which may be due to factors such as demyelination of nerve fibres, reduced painful physical activity, improved coping, or associated co-morbidities that distract from HS-related pain.